Thanks to RFC's diecast, we've got a quick video on his RFC Reviews channel showing the Power of The Primes toys on display during Hascon. One detail visible in this video that seems to have largely been overlooked is an Enigma of Combination shown at Grimlock's feet. Like the various forms of Matrix included with Leader toys, the Engimas are the special accessory component for the Voyager figures that within the function are what permit them to combine with the Deluxes. You can find the video embedded below, and a screenshot showing the Enigma. Keep reading!
As it happens, Starscream's Enigma of Combination was also visible the entire time with nobody catching on. It's in the packaged sample in the case. I've highlighted it in the cropped screencap below. Apparently nobody thought anything of that at the same time they were extracting the combiner hand from the packaged sample of Jazz on display. Starscream's Enigma doesn't look to have any paint, but Grimlock's is shown with a nice, if simple deco.